Wow a year old stump.
I use cinnamon too.
@deepsouth The stump is too short I think it can't be cut anymore?
I do not see "eyes/nodes" where branches normally grow.
If top is not rotted and it has stayed alive for a year old, try keeping it alive and maybe when it is big enough or tall enough, if it doesn't develop a branch, you can do a flat graft of a desert rose cultivar you like?
This is really strange and interesting so keep us posted.
Yes, I will keep it out of the full sun for now but agree with James partial sun may be okay. I moved mine to where they get morning sun only. Also plastic pots get too hot on direct sun.